1. Field of the Invention
In general, the invention relates to hinges and joints for eyewear.
2. Description of Related Art
Eyeglasses, also called eyewear, have a dual role that is an amalgam of function and fashion. Simply put, one's glasses correct vision, but they are usually chosen because of how they look, or how they complement the wearer's face. Yet although they may be viewed as a fashion accessory, they are an unusual one—a typical pair of glasses may need to survive multiple years of daily wear. In addition, some eyeglasses are specifically designed as safety wear, with lenses and frames designed to sustain impacts or protect the wearer's eyes from certain wavelengths of light.
The joints, hinges, and other components of eyeglass frames are often small. Small components, if not engineered well, may fail outright during use.
Even if the components are well engineered, wear can cause problems with small components. For example, the lens rims of most metal eyeglass frames are split, with the portion of the frame that encircles each lens divided, so that the lens can be inserted. Once the lens is inserted, the two parts of the frame are usually secured together with a small screw. That screw is often under tension, has tiny threads, and can come loose over time, causing a lens to loosen and creating a major inconvenience for the wearer.